1. Field of the Invention
The present invention is in the field of gas laser, particularly continuous wave (CW) lasers pumped by means of a radio-frequency electromagnetic wave generator. The generator is coupled to the lasing gas by means of the electrodes which form a transmission line in a gas containment structure. The gas containment structure is usually a hybride dielectric/metal structure which, in combination with the electrodes also serves as an optical waveguide for the laser output.
2. Prior Art
Numerous systems have been proposed for gas lasers. For high power applications the ionized N.sub.2 --CO.sub.2 --He.sub.2 laser has proved to be very efficient. The highest powers are achieved with pre-ionized flowing gas, but these are large and cumbersome. Low to medium power applications employ a more convenient arrangement wherein the gas is enclosed and excited in hybrid dielectric/metal optical waveguide containing at least one spaced parallel pair of ionizing electrodes. By using uniform long narrow electrodes, a large ionization region is formed. Such electrodes and ionized gas also provide a transmission line with a characteristic impedance that can be matched to the impedance of a radio-frequency (RF) source of electromagnetic waves to provide the required ionizing potentials. A key to the efficient operation of this laser is the free mobility of the molecules which must cool between emissions by colliding with their surroundings. Unfortunately, a good percentage of this mobility is lost by collision with other molecules which does not always produce useful results. There currently exists no effective passive means of removing the hot gas from the waveguide in the time required for reasonable cooling efficiency.